2 fuel pumps, 1 big problem

[240Zdragon72]

ok, this is a big pain in the butt. I am getting spark all the way to the plugs. now, no power to the fuel pump. Wouldn't I hear it turn on when I put the key to on? Also, is the stock fuel pump in the tank? The car is a 240 w/ L28 and T5 trans. SU carbs and distributor module. What the :tapemouth is wrong with my car?? I love this car, but she is really being a pain!

Thanks,

Brian:alien:

[LanceM]

Hi Brian,

The stock electric fuel pump is mounted to the chassie in front of the fuel tank on the passengers side. If I remember correctly the electric fuel pump only runs after the engine reaches 600 rpm or so. This is a safety feature so if in an accident the fuel line ruptures and the engine is stopped the pump won't empty the fuel tank just because the key is on.

[240Zdragon72]

Lance,

Thanks for the tips. I'll post another reply if I get anything working.

Brian:alien:

[tanny]

My electric fuel pump(73 240z) runs as soon as the ignition is turned on, but I noticed that the PO rewired it, so I don't know if that's normal.. That's why I installed a fuel pump shutoff switch from a Ford. Victor.

[carguyinok]

ok, this is a big pain in the butt. I am getting spark all the way to the plugs. now, no power to the fuel pump. Wouldn't I hear it turn on when I put the key to on? Also, is the stock fuel pump in the tank? The car is a 240 w/ L28 and T5 trans. SU carbs and distributor module. What the is wrong with my car?? I love this car, but she is really being a pain!

Is your mechanical pump working? Why the major hit on the elec fuel pump ? If you are not getting fuel to the mechanical pump that is not neccessarily the fault of your elec. fuel pump. For that matter the fuel pump your looking at is not NEEDED for the car to get fuel. The mechanical pump is up to the job on its own and can even pull fuel through the non working elec. pump. Not that I would just toss the elec pump :stupid:

The Z cars are known for BAD BAD BAD gas tanks, pluged fuel filters, and lines. I would start with pulling the intake fuel line from the mechanical pump and blow air down the fuel line. Then hook it back up and see if you are getting fuel.

I would put a new fuel filter on at the same time if you have not already done this. If you have not put a new one on yet keep the old one and bust it open and see what is on the filter. I have seen them look like mud inside.

You can also run a line from a gas can to the mechanical pump and see if its working.

Hope this helps, I know how much of a headache this can be.

[sblake01]

240z's didn't have electric fuel pumps. 260z's had a mechanical as well as a suplimentary electric fuel pump. 280z's have an electric fuel pump only since they are fuel injected. If you car has an electric fuel pump, someone added it on. If you also have a mechanical fuel pump check to see if eccentric that drives it is there in front of the camshaft gear. I say this because you say you have an L28 which would have been originally fuel injected and would not have the eccentric installed. Therefore, there would be nothing to drive the mechanical fuel pump. Anyway, there would be no relay unless the person who installed the electric fuel pump added one. An add on electric fuel pump is usually wired to the 'on' side of the ignition switch. The problem, like Victor said, is that fuel is being pumped whenever the ignition is on whether or not the engine is running so I would also put a cutoff swithch in that power line to the fuel pump.

Stephen Blakeney

1979 810 2dr

1978 280Z coupe

1964 L320 pickup

[tanny]

I'm not sure of the exact history, but the 73 240 came with both mechanical and electric pumps. I don't know if the electric was put on by the dealers or if it came from the factory that way. I know plenty of people on this site would know the answer. Victor.

[sblake01]

I stand corrected. That's what I get for trusting my memory!

Steve.

[tanny]

I can't remember if I even have a memory. Victor(or is that Tony? Hiram?)

[frank13]

The 1973 did have an electric pump. Even '72 and '71's have the electrical connections for them back at the tank harness. Wrap up in blue tape next to the fuel level sender. That has been stated on this site before. I remember seeing it in a thread before. But since my first Z was a '73 I know it for fact. Not sure if a '70-69 had this connector? I believe that one of the main reasons for the supplemental pump had to do with the nasty vapor lock conditions that the had(have). But for 240's the pump would prime the system regardless of a hot soak condition. Or that's what I learned as my experience with this car started. :devious:

[beandip]

I have memtioned this before , a easy fix is a pump from a carbed RX-7 , they are as quiet as the oem and pump the correct pressure and plenty of volume . Quiet is some thing several after mkt. pumps are not, and $15.00 at the bone yard is not a bad deal. :classic:

[frank13]

Hey Beandip, is that a first Gen 12A Rx-7? :devious: